Oxidación de un modelo de lignina mediante reacción de Fenton en ausencia de agua.
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Date
2025
Journal Title
Journal ISSN
Volume Title
Publisher
Universidad de Concepción
Abstract
La biomasa proveniente de la industria forestal se ha mostrado como una potencial opción para reemplazar los productos o precursores químicos que hoy en día se obtienen de la industria del petróleo. En particular, la lignina ha suscitado interés debido a su potencial para la producción de productos químicos a partir de una fuente renovable. A través de los años se han investigado posibles formas para poder despolimerizarla, con el objetivo de encontrar una plataforma de bioproductos. Los procesos que se han explorado requieren de mucha energía o no han mostrado buenos resultados. Según la literatura, el objetivo en general de estos procesos es romper el enlace que más abundante en esta estructura, el cual es el enlace β-O-4.
Los procesos de oxidación avanzada (POAs), se han mostrado como una posible vía para degradar lignina debido a su uso en la degradación de diferentes contaminantes orgánicos. La reacción de Fenton, una reacción que es parte de los POAs, se ha visto como una alternativa para llevar a cabo la degradación de la lignina debido a sus bajos costes y versatilidad. Sin embargo, la aplicación de esta reacción se limita a matrices acuosas, dado esto, en su forma convencional no es posible la degradación de la lignina o sus modelos, ya que estas especies presentan insolubilidad en agua.
Por lo descrito anteriormente, es que en este trabajo de investigación se evaluó la eficiencia de oxidación de la reacción de Fenton en un medio no acuoso como el CH3COOH y que sus reactivos no contengan agua en ninguna de sus componentes, logrando una oxidación del modelo comercial del enlace β-O-4, con porcentajes entre 18-20%, observando actividad radicalaria de •OH y •SO4, e identificando productos de oxidación, mayoritariamente aromáticos.
Biomass from the forestry industry has emerged as a potential alternative to replace products or chemical precursors derived from the petroleum industry. Lignin has garnered significant interest due to its potential as a renewable source for producing value-added chemicals. Over the years, several strategies for its depolymerization have been investigated to establish a bioproducts platform. However, the processes explored often require high energy input or have shown limited efficiency. According to the literature, the general objective of these processes is to cleave the most abundant linkage in the lignin structure, the β-O-4 bond. Advanced oxidation processes (AOPs) have been proposed as a potential route for lignin degradation due to their successful application in the degradation of various organic pollutants. The Fenton reaction, a representative AOP, has been considered a promising alternative for lignin degradation because of its low cost and versatility. Nevertheless, its application is restricted to aqueous matrices. Consequently, in its conventional form, the degradation of lignin or its model compounds is not feasible, as these species are insoluble in water. Based on this background, the present study evaluated the oxidation efficiency of the Fenton reaction in a non-aqueous medium, specifically CH₃COOH, ensuring no water was present in any of the components. Under these conditions, the oxidation of a commercial β-O-4 model compound was achieved, with yields ranging between 18–20%. Radical activity from •OH and •SO4 was detected, and oxidation products, mainly aromatic compounds, were identified.
Biomass from the forestry industry has emerged as a potential alternative to replace products or chemical precursors derived from the petroleum industry. Lignin has garnered significant interest due to its potential as a renewable source for producing value-added chemicals. Over the years, several strategies for its depolymerization have been investigated to establish a bioproducts platform. However, the processes explored often require high energy input or have shown limited efficiency. According to the literature, the general objective of these processes is to cleave the most abundant linkage in the lignin structure, the β-O-4 bond. Advanced oxidation processes (AOPs) have been proposed as a potential route for lignin degradation due to their successful application in the degradation of various organic pollutants. The Fenton reaction, a representative AOP, has been considered a promising alternative for lignin degradation because of its low cost and versatility. Nevertheless, its application is restricted to aqueous matrices. Consequently, in its conventional form, the degradation of lignin or its model compounds is not feasible, as these species are insoluble in water. Based on this background, the present study evaluated the oxidation efficiency of the Fenton reaction in a non-aqueous medium, specifically CH₃COOH, ensuring no water was present in any of the components. Under these conditions, the oxidation of a commercial β-O-4 model compound was achieved, with yields ranging between 18–20%. Radical activity from •OH and •SO4 was detected, and oxidation products, mainly aromatic compounds, were identified.
Description
Tesis presentada para optar al grado de Magíster en Ciencias con mención en Química.
Keywords
Biomasa, Industria de productos forestales, Lignina, Oxidación